“After past storms, we’ve seen as many as 50 percent of the vehicles resold as whole units. Whether or not those vehicles were properly disclosed as water damaged is a serious concern,” Carfax’s Larry Gamache told WCBS 880’s Marla Diamond.

Experts said that beneath the surface, water can damage computers that control everything from the gas pedal to the airbags.

“Flood damaged vehicles are incredibly dangerous. There’s no predicting the kinds of mechanical and safety issues a flood-damaged car is going to develop so we think it’s just imperative that consumers protect themselves,” Gamache told Diamond.

Insurance companies believe early estimates that more than 600,000 cars sustained flood damage from Sandy were exaggerated. The number, insurance companies said, is likely closer to 50,000, Diamond reported.

Carfax provides vehicle history reports that detail any damage sustained that may or may not be visible.